New Iron–Mercury Clusters: [Hg7{Fe(CO)4}5(StBu)3Cl], [Hg14Fe12{Fe(CO)4}6S6(StBu)8Br18], and [Hg39Fe8{Fe(CO)4}18S8(StBu)14Br28]

Three new chalcogen-bridged mercury–iron clusters with 7, 14, and 39 mercury centers were obtained from the reaction of tBuSSiMe₃ with [Fe(CO)₄(HgX)₂] (X= Cl, Br). The compounds were isolated in the form of orange crystals that were characterized by X-ray crystallography. The picture on the right shows the structure of the heavy-atom skeleton of [Hg₁₄Fe₁₂{Fe(CO)₄}₆S₆(StBu)₈Br₁₈] (Hg, Fe, Br, and S are black, diagonally striped, white, and horizontally striped, respectively).     

Ba5Cl4(H2O)8(VPO5)8: a novel three‐dimensional framework solid

The novel hydrothermally synthesized title compound, pentabarium tetrachloride octahydrate octakis(oxovanadium phosphate), Ba₅Cl₄(H₂O)₈(VPO₅)₈, crystallizes in the orthorhombic space group Cmca with a unit cell containing four formula units. Two Ba²⁺ cations, two Cl⁻ anions and the O atoms of four water molecules are situated on the (100) mirror plane, while the third independent Ba²⁺ cation is on the intersection of the (100) plane and the twofold axis parallel to a. Two phosphate P atoms are on twofold axes, while the remaining independent P atom and both V atoms are in general positions. The structure is characterized by two kinds of layers, namely anionic oxovanadium phosphate (VPO₅), composed of corner‐sharing VO₅ square pyramids and PO₄ tetrahedra, and cationic barium chloride hydrate clusters, Ba₅Cl₄(H₂O)₈, composed of three Ba²⁺ cations linked by bridging chloride anions. The layers are connected by Ba—O bonds to generate a three‐dimensional structure.     

(CH3)4N][(C5H5NH)0.8((CH3)3NH)0.2]U2Si9O23F4 (USH-8): an organically templated open-framework uranium silicate

The open-framework uranium fluorosilicate [(CH3)4N][(C5H5NH)0.8((CH3)3NH)0.2]U2Si9O23F4 (USH-8) has been synthesized hydrothermally by using tetramethylammonium hydroxide and pyridine-HF. The compound has a framework composition U2Si9O23F4 based on silicate double layers that are linked by chains of UO3F4 pentagonal bipyramids. The framework has 12-ring channels along [010] and 7-ring channels along [100]. The [010] 12-ring channels have a calabash-shape with the middle part partially blocked by the uranyl oxygen atoms. The narrow side of the 12-ring channels is occupied by well-ordered TMA cations while the wide side is occupied by disordered pyridinium and trimethylammonium cations.     

New class of ruthenium sulfide clusters: Ru(4)S(6)(PPh(3))(4), Ru(5)S(6)(PPh(3))(5), and Ru(6)S(8)(PPh(3))(6)

Reaction of RuCl(2)(PPh(3))(3) with S(2)(-) sources yields a family of phosphine-containing Ru-S clusters which have been characterized crystallographically and by MALDI-MS. Ru(4)S(6)(PPh(3))(4) (Ru-Ru(av) = 2.94 A) has idealized T(d)() symmetry whereas Ru(6)S(8)(PPh(3))(6) (Ru-Ru(av) = 2.82 A) adopts the idealized O(h)() symmetry characteristic of Chevrel clusters. Ru(5)S(6)(PPh(3))(5) is formally derived by the addition of Ru(PPh(3)) to one face of Ru(4)S(6)(PPh(3))(4). In terms of its M-S connectivity, the Ru(5)S(6) cluster resembles a fragment of the FeMo cluster in nitrogenase.     

Tetramethylammoniumamalgam, [N(CH3)4]Hg8

Tetramethyl Ammonium Amalgam, [N(CH₃)₄]Hg₈ Crystals of tetramethyl ammonium amalgam with the composition [N(CH₃)₄]Hg₈ were prepared by electrolysis. According to temperature‐dependent X‐ray diffraction experiments the compound transforms into an amorphous product above 6 °C; the decomposition is a multi‐stage process as shown by DTA experiments. X‐ray examinations of crystalline aggregates indicate a structure of low symmetry with remarkable similarities to that of α‐Hg.     

Darstellung und Kristallstruktur von Ba3CdSn2S8 mit einer Anmerkung über Ba6CdAg2Sn4S16

Preparation and Crystal Structure of Ba₃CdSn₂S₈ Including a Notation about Ba₆CdAg₂Sn₄S₁₆ Ba₃CdSn₂S₈ (A) and Ba₆CdAg₂Sn₄S₁₆ (B) were prepared for the first time and the crystal structure was determined using single crystal data of (A). (A) and (B) are isotypic. Space group and lattice constants see “Inhaltsübersicht”. The crystal structure is described and discussed.     

Ein neues Oxometallat mit Mangan(II): Ba5Mn4Nd8O21

On a New Oxometallate of Manganese (II): Ba₅Mn₄Nd₈O₂₁ Single crystals of Ba₅Mn₄Nd₈O₂₁ were prepared for the first time by CO₂-Laser technique using H₂-atmosphere. It was investigated by a single crystal X-ray diffractometer study. Ba₅Mn₄Nd₈O₂₁ crystallizes with tetragonal symmetry space group: C? I4/m; a = 14.2104 Å; c = 5.8581 Å; Z = 2. Mn²⁺ is found in square pyramids of oxygen.     

Syntheses,Crystal Structures,and Properties of the Novel Thioborates KBa4(BS3)3 and K4Ba11(BS3)8S

Our systematic studies on quaternary thioborates containing both a comparably small alkali metal ion and a large alkaline earth cation lead to the two new crystalline phases KBa₄(BS₃)₃ and K₄Ba₁₁(BS₃)₈S. The former consists of isolated BS₃ units and the corresponding counter‐ions while in the latter BS₃^3– and S^2– anions coexist. In both compounds boron is found in a trigonal‐planar coordination, in the case of K₄Ba₁₁(BS₃)₈S the additional sulfide anions are located inside an octahedron built of six barium cations. The two compounds were prepared in solid state reactions from the metal sulfides, amorphous boron and sulfur. Evacuated carbon coated silica tubes were used as reaction vessels since temperatures up to 870 K were applied. KBa₄(BS₃)₃ crystallizes in the monoclinic space group C 2/c (no. 15) with a = 14.299(6) Å, b = 8.808(3) Å, c = 13.656(5) Å, β = 98.72(4)°, and Z = 4, while for K₄Ba₁₁(BS₃)₈S the trigonal space group R 3 c (no. 167) was found with a = 18.146(3) Å, c = 25.980(7) Å, and Z = 6. X‐ray powder patterns are compared to calculated diffraction data obtained from single crystal X‐ray structure determination, in the case of K₄Ba₁₁(BS₃)₈S vibrational spectra were recorded.     

First characterization of the ammine-ammonium complex [(NH4(NH3)4)2(mu-NH3)2]2+ in the crystal structure of [NH4(NH3)4][B(C6H5)4].NH3 and the [NH4(NH3)4]+ complex in [NH4(NH3)4][Ca(NH3)7]As3S6.2NH3 and [NH4(NH3)4][Ba(NH3)8]As3S6.NH3

The compound [NH4(NH3)4][B(C6H5)4].NH3 (1) was prepared by the reaction of NaB(C(6)H(5))(4) with a proton-charged ion-exchange resin in liquid ammonia. [NH(4)(NH(3))(4)][Ca(NH(3))(7)]As(3)S(6).2NH(3) (2) and [NH4(NH3)4][Ba(NH3)8]As3S6.NH3 (3) were synthesized by reduction of As(4)S(4) with Ca and Ba in liquid ammonia. All ammoniates were characterized by low-temperature single-crystal X-ray structure analysis. They were found to contain the ammine-ammonium complex with the maximal possible number of coordinating ammonia molecules, the [NH4(NH3)4]+ ion. 1 contains a special dimer, the [(NH4(NH3)4)2(mu-NH3)2]2+ ion, which is formed by two[NH4(NH3)4]+ ions linked by two ammonia molecules. The H(3)N-H...N hydrogen bonds in all three compounds range from 1.82 to 2.20 A (DHA = Donor-H...Acceptor angles: 156-178 degrees). In 2 and 3, additional H(2)N-H...S bonds to the thioanions are observed, ranging between 2.49 and 3.00 A (DHA angles: 120-175 degrees). Two parallel phenyl rings of the [B(C(6)H(5))(4)](-) anion in 1 form a pi...pi hydrogen bond (C...C distance, 3.38 A; DHA angles, 82 degrees), leading to a dimeric [B(C6H5)4]2(2-) ion.     

Kinetics of oxidation of “V5S8” and V3S4

The kinetics of oxidation of V₅S₈ and V₃S₄ to V₂O₃ were studied by using both isothermal and nonisothermal thermogravimetry in the oxygen partial pressure range from 1.0×10^–1 to 1.0×10^–3 atm. The kinetic equation describing the oxidation process was found to bekt=1-(1–)^1/1.5 and was valid for the fraction of sample reacted=0 to 80–95%. The activation energy was found to be from 45.9 to 27.8 kJ/mol^–1 for V₅S₈, and from 46.8 to 29.0 kj/mol^–1 for V₃S₄ over the temperature range 375 to 500°. The relationship between rate constantk andPO₂ was also determined.

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Zusammenfassung Die Kinetik der Oxydation von V₅S₈ und V₃S₄ zu V₂O₃ wurde mittels isothermer und nicht-isothermer Thermogravimetrie bei Sauerstoffpartialdrücken von 1·10^–1 bis 1·10^–3 atm untersucht. Die den Oxydationsprozeß beschreibende kinetische Gleichungkt=1-(1-)^1/1,5 ist bis zu einem Umsatzgrad von 80–95% gültig. Im Temperaturbereich von 375–500° liegt der Wert der Aktivierungsenergie für V₅S₈ zwischen 45,9 und 27,8 kj mol^–1 und der für V₃S₄ zwischen 46,8 und 29,0 kJ/mol^–1. Die Beziehung zwischen der Geschwindigkeitskonstantek undPO₂ wurde ebenfalls ermittelt.

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« V₅S₈» V₃S₄ V₂O₃ 0,1 0,003 . t=1–(1–)^1/1.5 0-80-95%. 375–500° «V₅S₈» 45,9–28,8 - ^–1, V₃S₄ — 46,8-29,0 ·^–1. .

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The authors wish to thank Dr. T. Uchida for his computer programming assistance.     

Novel Alkaline Earth Metal Chalcogenoborates: Syntheses and Crystal Structures of Sr4.2Ba2.8(BS3)4S and Ba7(BSe3)4Se

Systematic studies on quaternary thio‐ and selenoborates containing heavier alkaline earth metal cations led to the two new isotypic crystalline phases Sr_4.2Ba_2.8(BS₃)₄S and Ba₇(BSe₃)₄Se. Both compounds consist of trigonal‐planar BQ₃ (Q = S, Se) units, isolated Q^2– anions and the corresponding counter‐ions. The two new chalcogenoborates were prepared in solid state reactions from the metal sulfides (selenides), amorphous boron and sulfur (selenium). Evacuated carbon coated silica tubes were used as reaction vessels since temperatures up to 870 K were applied. Sr_4.2Ba_2.8(BS₃)₄S and Ba₇(BSe₃)₄Se crystallize in the monoclinic space group C2/c (no. 15) with a = 9.902(3) Å, b = 23.504(9) Å, c = 9.884(3) Å, β = 90.01(3)° and Z = 4 in the case of the thioborate, while for the selenoborate the lattice parameters a = 10.513(2) Å, b = 25.021(5) Å, c = 10.513(2) Å, β = 90.10(3)° were determined. X‐ray powder patterns are compared to calculated diffraction data obtained from single crystal X‐ray structure determination.     

Pb5In3Bi5S17 [Pb4.94(3)In3.05(3)Bi4.99(3)S17] and its structural relationship with Pb4In3Bi7S18

The title phase (pentalead triindium pentabismuth heptadecasulfide) has been synthesized and structurally characterized. Its structure contains mixed Bi/In, In/Bi and Pb/In positions; all atoms lie on crystallographic mirror planes. The structural relationship between Pb₅In₃Bi₅S₁₇ and a phase known by the formula Pb₄In₃Bi₇S₁₈ is discussed. A comparatively large and complex structural `seed' is defined which is common to both phases. The structural changes within this seed when moving from one phase to the other are described by graphical means.     

Novel Heterometallic Polymers Induced by Host-Guest Cations: X-ray Structures of [(18-crown-6)KAgWS4]n and [{ (18-crown-6)Ba(DMF)4}(Ag2W2S8)]n

Abstract

α-Keto acids have characteristic unpleasant smell and chemical instability, which makes the usages of the materials difficult for pharmaceutical purposes. However, the inclusion compounds of the acids with cyclodextrins have no or slight smell and are chemically stable. Especially, an inclusion compound of optically active s-α-keto-β-methylvaleric acids (S-KMV) kept its activity for at least 120 days at room temperature, unlike its salt of basic amino acid. We tried to investigate the solid state structure of the inclusion compounds S-KMV / β-CD by the use of CPMAS ¹³C NMR spectroscopy. The comparison of the spectra of S-KMV / β-CD and KMV·1/2Ca·H₂O suggested that the S-KMV molecule is not so tightly included inside the β-CD cavity, but as a result of rotational isomerism restriction, it exists in a single conformer.